Answer:
a single-replacement reaction replaces one element for another in a compound. A double-replacement reaction exchanges the cations, or the anions, of two ionic compounds.
False
Explanation:
Electron affinity is negative when energy is absorbed and it is positive when energy is released.
Electron affinity is defined as the energy released in adding an electron to a neutral atom in the gas phase.
It is a measure of the readiness of an atom to gain an electron.
In a reaction where energy is released, electron affinity is usually positive. These reactions are called exothermic reactions.
Endothermic reactions in which energy is absorbed have negative electron affinity values.
Learn more:
Endothermic reactions brainly.com/question/12964401
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<span>The right answer is D. In a situation where the sound wave reaches the ear and the reflected wave reaches the ear less than 0.1 seconds later, the individual would not be able to hear an echo. There needs to a far more significant delay between the sound and the reflection of said sound reaching the listener's ear for the echo effect to become apparent.</span>
